Gas-fired melting-furnace.



W. G. KRANZ.

GAS FIRED MBLTING PURNAGE.

APPLICATION FILED 001216, 1508.

Patented July 8, 1913.

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WITNESSES W. G. KRANZ.

GAS PIRED MBLTING FURNAGE. APPLICATION IILIID 00T. I', 100s.

Patented July 8, 1913 4 SHEETS-SHEET 2.

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W. G. KRANZ.

GAS FIRED MELTING PURNAGE. APPLIoATloN FILED o0T.1, 1908.

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WILLIAM G. KRANZ, OF SHARON,`PENNSYLVANIA, .ASSIGNOR TO THE NATIONALMAL- LEABLE CASTINGS COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

GAS-FIRED MELTING-FURNACE.

Specification of Letters Patent.

Patented July 8, 1913.

Application filed October 1G, 1908. Serial No. 458,053.

To all lwhom t may concern:

Be it known that I, lVILhIAM G. Kama, of Sharon, in the county of Mercerand State of Pennsylvania, have invented a new and useful Improvement inGas-Fired M elting-l1`urnaces, of which the following is a full, clear,and exact description, reference being had to the accompanying drawings,in which- Figure l is a vertical longitudinal section of a furmtceconstructed ill-accordance with my invention; Fig. 2 is a horizontalsection partly in plan view on thexirregular line II-ll ol' Fig. 1; Fig.3 is a vertical section on the line III-lll of Figs. 1, 2 and 6; Fig. Llis a lvertical section on the line IV#- IV of Figs. 1, 2 and 6; Fig. 5is a vertical section on the`liI1eV-V of Figs. l and 2; and Fig. (S isaf vertical section on the `line VI-VI of Fig. 3.y

The purpose of m invention is to provide a furnace for tie eflieientmelting of pig iron foruse in the manufacture of malleable castings,which operation must be carried on with uniformity, so as to produce arefuilar and uniform product of castings, and for this reason a properconstruction ot' furnace is of great importance. My furnace has provedvery eheient for these pu`rposes.

In the drawings, 22 represents the hearth ont the meltingr furnacehavinga reverber: tory roof 8, as shown, and fl is a gas producerchamber, which huilt directly at the front end ofl the furnace, with itsdischarge flue 5 discharging the gases directly linto the furnacethroat.

6 is the hopper of the producer, and 7 are the blower-pipes. At the rearend of the furnace between the end of the hearth and the stack flue 8 isa recuperator chamber i), divided by vertical partition Vl0 into two ormore subchambers 9 and 9, through which the waste gases from the furnacepass rially on their way to the stack as indicated by dotted arrows inFig. l. 'In this recuperator are a series of transverse llnespreteraloly, built of tile. I show them arranged in four series 11, 11',11a and ll, which communicate at their ends with passages 12, l2 and 12lat one end of the recuperator and 12b and 12d at the opposite end of therecuperator. These passages are sepa' ratedfroln each other by -thevertical partition 10 and the horizontal partitions 13,

lf3a and lil", so that thc air which is admitted through the inlet 14.into the chamber l2 passes to the chamber 12" through the recupcrating[lues l1, thence to the passage l2 through the recuperatlng lilies ll',thence to the passage 1Q at the other end of the recupcratorthrough therecuperating lues l1, and thence similarly through the recupcratinglilies ll", thence downwardly through the passage l2" into an air liuclil, by which it is conducted to the air inlet ports 15, and emergingfromsaid ports-v the now heated air mixes with the producer gases fromthe producer port 5 and sup ports the combustion thereof.

As the air is expanded in its passage through the reeuperator lines, l.prefer to make the groups ol.E tlues successively larger or greater `innumber. Thus, in the group l1, l show live tlucs; in the group 11, sixtlu'cs; in the group 1l, sevcn'llucs; and in the group 1lb, ten llucs.These lines being highly heated by the waste gases passing through therecuperator on their way to the stack, give up.thc heat to the air,which is thus delivered to the 'furnace in a heated condition andenhances the combustion ot the producer gas. l am enabled in this way torun the furnace with much less lucl than heretofore, and also to producemore uniform heating etl'ect than has heretofore been possible in theoperation ot such furnaces.

The construction is very compact and con-v he obtained from the ordinarycoal-iired reverberatory furnace, and at a ,less cost of lmelting thanwith an open hearth furnace.

By reconstructing the furnace with rccuperator chambers and usinggaseous fuel l get a furnace which gives more intenso heat than areverbcratory coal-fired furnace, costs less to construct than theopenhearth furnace and will afford much of the elliclency which can be hadotherwise only with the open hearth. Where coal is burned'directly in areverberatory lurnace the 1ron cannot be brought to the propertemperairon not. only with the open hearth furnace,

ture without skimming 0H the slag and subjecting the iron to a hot flameunder forced draft. This endangers the quality of the because of therapidly oxidizing nature of the flame, but also because the strong blastconveys a large amount of sulfur and ash from the coal to the iron, theiron not being protected by the slag. In the use of my furnaceso'intense is theheat and so uniformly distributed over the surface ofthe iron, that the slag can be left on the iron as a protection from thesulfur contained in the flame until the iron is all tapped "out of thefurnace, and yet the iron can be properly reduced and brought to aproper state of fluidity in as short a time as in a reverberatoryfurnace Where the slagis skimmed off.

With my furnace a manufacturer can re tain approximately the samemelting capacity as with the coal-tired reverberatory furnace, anddistribute the furnaces in the same way, and get the beneiits of theopen hearth furnace With a furnace costing less to build and easier tooperate, and in one respect get a result which could not be obtained Inthe open hearth 'the gas is reversed from time to time during therefining process so as to heat the incoming gas and air by means of thechecker work whieh'has been heated by the outgoing burning gases, but aslong as the gas and air are entering through the chamber on one sidethat chamber is being cooled .otl' and whenI the gas is again reversedit starts. through the other chamber at its maximum temperature, so thatthe temperature of the incoming gas and air fluctnates considerably. Inmy furnace the air is heated by continuously passing through `the sameseries of fines and is gradually increased in tenipcrature from thestart until it reaches its maximum, and is not subject to thefluctuations of the open hearth'. This is advantageousvin givinguniformity to the molten metal produced by the furnace. An-

located adjacent to t-he stack other advantage in this furnace over theoldA yversa much more readily and accurately,

than in the reverberatory furnace.

lVithin the scope of my invention, as dened in the claim, modificationsmay be made, since what I claim is A .gas-fired melting furnace having arecuperator chamber beyond its eXit end and between the furnace and thestack, a transverse partition wall extending upwardly Within the.recuperator chamber toward its upper end to give the gases up and downpasses therethrough, a plurality of passages atl each' end of therecuperator chamberl separated from each other, groups yof air iluesextending transversely through the recuperator compartments, the firstgroup being and the last group being located adjacent to the openingfroin the furnace to the recuperating chamber, the passages and groupsof lues being arranged to give the air aserial passage throughsuccessive groups of the lues, land a return passage for the heated airleading rearwardly to the gas inlet-end of nace, the successive groupsof air ilues being arranged to give increased area to the flowof air.

In testimony whereof, I have hereunto set. my hand. y

WILLIAM G. KRANZ. Witnesses i Tnoiu as W BAKmvnLL II. M. Corwin.

the fur-

